Validate inputs

[crazybolillo]

The app eventually needs to validate stuff like:

• Endpoint IDs
• Endpoint Display Names
• Bouncer must prohibit calls to its own (endpoint dialing its own extension)

And probably other stuff that gets added in the future.

[crazybolillo]

Possible validation for user:

1. ID: May only contain lowercase alphanumeric characters, hyphens, dots and underscores. 64 character limit. Examples of valid users could be:

   • john.doe
   • john77
   • 4005 (please don't do this)
   • john_doe
   • john-doe

2. Display Name: Allow all characters besides special ones, like <>@;. 64 character limit

3. Password: Min length of 12 characters, max of 128, just to have a limit.

4. Context: Alphanumeric characters, max of 64.

5. Transport: Alphanumeric characters, hyphens and underscores. Max of 64

6. Max contacts: Equal or bigger than 1.

7. Extension: At least one digit long, up to 6. It is a string but it should only have digits.

[crazybolillo]

Also, if validations are going to be performed, helpful error messages should be provided.